<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<meta name="viewport" content="width=device-width, initial-scale=1">
	<title></title>
</head>
<body>

<script type="text/javascript">
/*
var num=10; //内存分配
alert(num); //内存使
num=null; //内存回收
*/

//基本
var a='你好js';
var b=10;
var c=true;
var d=undefined;
var e=null;
//引用
var g=function(){}
var f=[1,2,2,3];

//栈内存
var a=10;
var b=a;
b=20;



</script>

</body>
</html>